where did you hear that?
there are many old wives tales; some of which were invented to stop you from enjoying masterbation, as it was thought of as being depraved and dirty.... you probably know the one about making you blind...??

the only thing regular masturbation might do is make you zinc deficient. apparently men lose zinc every time they ejaculate, so often are zinc deficient. don't know if zinc deficiency is related to hair loss but if it is, as that other guy said, it's surprising men have any hair left at all....